How to convert JSON to Protocol Buffers (protobuf) in JavaScript.

24 Sep 2023

ProtocolBuffers

Protocol Buffers (protobuf) is a language-agnostic binary serialization format widely used in systems and applications requiring efficient data interchange. In this blog post, we will explore how to convert JSON data into Protocol Buffers using JavaScript.

Prerequisites

Before we begin, make sure you have the following prerequisites:

Basic understanding of JavaScript
Familiarity with JSON and Protocol Buffers concepts
Node.js installed on your development machine

Step 1: Setting up the project

First, let’s set up our project by creating a new directory and initializing a Node.js project.

Create a new directory for your project:

 mkdir json-to-protobuf-js
 cd json-to-protobuf-js

Initialize the Node.js project by running the following command:
```
 npm init -y
```

Step 2: Installing dependencies

To convert JSON to Protocol Buffers in JavaScript, we need to install the protobufjs library. Execute the following command in your project directory to install the library:

npm install protobufjs

Step 3: Creating the Protocol Buffers schema

Next, let’s define a Protocol Buffers schema that matches the structure of your JSON data. Create a new file called schema.proto in your project directory with the following contents:

syntax = "proto3";

message MyData {
  string name = 1;
  int32 age = 2;
  repeated string hobbies = 3;
}

The above schema defines a MyData message with name, age, and hobbies fields.

Step 4: Converting JSON to Protocol Buffers

In this step, we will write the JavaScript code to convert JSON data into Protocol Buffers format.

Create a new file called convert.js in your project directory and add the following code:

const protobuf = require('protobufjs');
const fs = require('fs');

// Read the Protocol Buffers schema from file
const schema = fs.readFileSync('./schema.proto', 'utf-8');

// Load the schema into protobuf.js
const root = protobuf.parse(schema).root;
const MyData = root.lookupType('MyData');

// JSON data to be converted
const jsonData = {
  name: 'John Doe',
  age: 25,
  hobbies: ['coding', 'gaming', 'reading']
};

// Encode the JSON data into Protocol Buffers format
const message = MyData.create(jsonData);
const buffer = MyData.encode(message).finish();

// Write the buffer to a file
fs.writeFileSync('./data.bin', buffer);

The above code imports the required libraries, reads the Protocol Buffers schema, loads it using protobufjs, defines the MyData message type, and converts the JSON data into Protocol Buffers format.

To run the script, execute the following command:

node convert.js

After running the script, you will find a data.bin file in your project directory containing the converted Protocol Buffers data.

Conclusion

In this blog post, we learned how to convert JSON data to Protocol Buffers (protobuf) format using JavaScript and the protobufjs library. You can now efficiently transfer structured data between different systems by utilizing the benefits of Protocol Buffers.

Give it a try in your own projects and see how Protocol Buffers can improve your data interchange performance and efficiency.

#JavaScript #ProtocolBuffers